18 Oct 2013 - Radioactivity levels in a well near a storage tank at the Fukushima nuclear power plant in Japan have risen immensely on Thursday, the plant’s operator has reported. Officials of the Tokyo Electric Power Company (TEPCO) said on Friday they detected 400,000 becquerels per liter of beta ray-emitting radioactive substances - including strontium - at the site, a level 6,500 times higher than readings taken on Wednesday, NHK World reported. The storage tank leaked over 300 tons of contaminated radioactive water in August, some of which is believed to have found its way into the sea through a ditch.